1. Technical Field
One or more exemplary embodiments relates to a method and apparatus for encoding and decoding motion information, and more particularly, to a method and apparatus for effectively encoding and decoding motion information of a current prediction unit.
2. Prior Art
Recently, as high definition video contents have become widely used, a need for a video codec having a higher coding efficiency than a conventional video codec such as MPEG-4 H.264/MPEG-4 advanced video coding (AVC) has increased.
According to motion compensation that is a technology for removing temporal redundancy in a video signal, compression efficiency is increased by transmitting a residual signal that is a difference value between an original video signal and a reference signal indicated by a motion vector. In general, a motion vector and a residual value of each block, as an encoding result obtained by encoding each block by using motion compensation, are transmitted to a decoder. Since motion vectors of each block occupy a considerable amount of an encoded bitstream, information about a motion vector assigned to each block needs to be reduced in order to increase compression efficiency.
In order to reduce transmission overhead during encoding of a motion vector, a motion vector of a previous block is used as a prediction motion vector of a current block in a conventional MPEG-2 codec, and a median of motion vectors of previously encoded blocks that are adjacent to a left side, an upper side, and an above-right side of a current block is used as a prediction motion vector of the current block in a codec such as MPEG-4 H.264/MPEG-4 AVC.